Openings such as joints, voids, gaps, or other discontinuities between two or more adjacent structural elements are present in buildings to accommodate building movements. Movements can occur between the adjacent structural elements, for example due to loads, heat, wind, and seismic events. These openings are sometimes referred to as dynamic joints, since they change (expand and contact or flex) over time.
There is a growing emergence of building codes and design guidelines specifying a minimum Sound Transmission Class (STC) rating within a building. There are also guidelines in international building codes for smoke partitions and smoke barriers. The openings within building structures can act as conduits for the passage of sound and smoke within commercial structures (e.g., apartments, office buildings, schools, etc.).